Major Events in the History of EarthCenozoic

Humans

Land plants

Animals Origin of solarsystem andEarth

Multicellular

1 4Proterozoic

eonArchaean

eon

Multicellulareukaryotes

Single-celledk t

2 3

Prokaryotes

eukaryotesAtmospheric oxygen

Classification systems

5 Kingdom system 3 Domain systemg y y1. Monera 1. Bacteria

2 Archaea2. Archaea2. Protista 3. Eukarya3. Fungi4. Animalia5. Plantae

Prokaryotes vs eukaryotesProkaryotes vs. eukaryotesUnicellular vs. multicellular

t t hi h t t hiautotrophic vs. heterotrophic

BacteriaU i ll l k t (l k l )- Unicellular prokaryotes (lack a nucleus)

- Three basic shapes: Bacillus, coccus, spirillum- Some are filamentous- Some are filamentous- Have a complex cell wall - some autotrophic others hetrotrophicp p- Found everywhere

ProtistaProtista

- Diverse organismsDiverse organisms

- Unicellular and multicellular and colonial

- Autotrophic (Phototrophic or chemitrophic) and hetrotrophichetrotrophic

- Mostly aquatic, anywhere there is water.Mostly aquatic, anywhere there is water.

- Many protists live as symbionts in other organisms.

ProtistaBottom–dwellers: attached or creepingDrift passively near the water surface (plankton)t pass e y ea t e ate su ace (p a to )

PhytoplanktonPhytoplankton - photosynthetic (planktonic algae and cyanobacteria) form the foundation of mostcyanobacteria) form the foundation of most marine and freshwater food webs - free–living speciesg p

Zooplankton- ProtozoaZooplankton Protozoa- heterotrophic

Early aquatic photosynthetic organisms :

- Prokaryotic Cyanobacteria- Eukaryotic algae

Unicellular ChlamydomonasyMulticellular Spirogyra

Cyanobacteria filamentous photosynthetic y p yprokaryote

Spirogyra filamentous photosynthetic algae, pond scumscum

FungigEukaryotic decomposers (heterotrophic)

found in many environments y- saltwater or fresh water- on landon land- cold or warm temperatures

Serve as a valuable ecological function by processing dead organic matterprocessing dead organic matter

Unicellular (yeast)M lti ll l fil t ( ld)Multicellular filamentous (mold)

Fungi evolved from an aquatic, flagellated ancestorA fungus usually consists of a mass of threadlike

hyphae called a mycelium

Hypha

Myceliumyce u

Fungi absorb food after digesting it outsideFungi absorb food after digesting it outside their bodies and absorb the nutrients

Fungal life cycles include asexual and sexualFungal life cycles include asexual and sexual stages

ASEXUAL- Haploid spores give rise to multi-cellular

filamentous haploid hyphae by mitosisp yp y

The haploid hyphae are made of mating- The haploid hyphae are made of mating types

Fungal groups differ in their life cycles and reproductive structuresKeyy

Haploid (n)Heterokaryotic (n + n)Diploid (2n)

Zygosporangium (n + n)

Mycelia ofdifferentmating types

Cells fuse2 3

Fusion ofnuclei

M i i

1

4MeiosisYoung zygosporangium(heterokaryotic) Sporangium

4

( y ) p gSpores (n)

SEXUAL in fruiting bodiesSEXUAL in fruiting bodies- Fusion of haploid hyphae produces a stage containing nuclei from two parentsstage containing nuclei from two parents heterokaryotic hyphae

- Nuclei fuse and undergo meiosis which produces haploid spores

Fungal groups have characteristic reproductive structures

Key 3 Diploid nucleiKeyHaploid (n)Heterokaryotic (n + n)Diploid (2n)

Fusion ofnuclei

Meiosis

3 Diploid nuclei

4 Sporesl d

Basidia Spores (n)Mushroom

released

Mushroom

2 G th f

5 Germination of sporesand growth of mycelia

1 Fusion of two hyphaeof different mating types

2 Growth ofheterokaryotic mycelium

Lichens consist of fungi living mutualisticallyLichens consist of fungi living mutualistically with photosynthetic organisms

Lichens consist of algae or cyanobacteria within aLichens consist of algae or cyanobacteria within a fungal network

Fungalhyphae

00

Algalcell

rized

SE

M 1

,00

Col

or

Early land photosynthetic organisms

Lichens- symbionts of a fungus and a photosynthetic organism either a cyanobacteria orphotosynthetic organism either a cyanobacteria or an algae

Th h h i l b i idThe photosynthetic algae or bacteria provide organic compounds which the fungus can use and the fungus provides support and protection for g p pp peither the algae or the bacteria.

Lichens can be found in the harshest ofLichens can be found in the harshest of environments on rocks